Establishing guidelines-based multidisciplinary diabetic limb salvage programme: A 100-day review of clinical characteristics and outcomes

Abstract

Objectives:

A newly established hospital in Singapore has introduced a pioneering multidisciplinary diabetic foot programme to provide comprehensive care for patients with diabetic foot ulcers. This study evaluates the early outcomes of a multidisciplinary diabetic limb salvage programme. Over the first 100 days of operation, the diabetic foot programme managed 106 patients.

Methods:

A descriptive statistical analysis was conducted to evaluate clinical characteristics and outcomes at 100 days of follow-up.

Results:

The majority of patients were Malay (46.2%) and male (61.3%), with a median age of 63.5 years. Most patients had long-standing diabetes and poor glycaemic control (77.8%), leading to high rates of diabetes-related complications. A total of 18.3% of patients had osteomyelitis, and 11.7% had gangrene. Of the 106 patients, 61.3% required inpatient management, 25.5% underwent revascularisation, and 34.9% had diabetic foot ulcer-related surgeries. According to Wound, Ischaemia and Foot Infection 12-month risk stratification, nearly 30% of patients were at medium to high risk of major lower extremity amputation. Minor lower extremity amputation occurred in 15.1% of patients and 4.7% required major lower extremity amputation. The 30-day mortality rate was 3.8%, and the average length of stay was 15.7 days. The time from admission to revascularisation was 4.4 days, and the time to diabetic foot ulcer-related surgery was 4.2 days. Wound healing was documented in 34.8% of patients at 100 days of follow-up, with a healing time of 63.2 days.

Conclusion:

Our guidelines based, multidisciplinary diabetic limb salvage programme demonstrated favourable limb salvage outcomes despite high predicted amputation risks. The early outcomes of this programme highlight the effectiveness of early medical optimisation, infection control, revascularisation and active wound care.

Introduction

Diabetic foot ulcers (DFUs) are among the most troubling complication of diabetes, with a lifetime incidence of up to 34% ¹ and is the leading cause of non-traumatic lower extremity amputation (LEA). Patients with DFU have a 5-year mortality rate of 30.5%, which is comparable to the pooled mortality of all cancer at 31.0%. ² Hence, efforts must be made to help alleviate this disease burden.

In Singapore, between 2021 to 2022, diabetes has a 8.5% prevalence among adults aged 18–69. ³ The International Diabetes Federation projects the diabetes prevalence in adults in Singapore would increase to 13.3% by 2030. ⁴ Compared to other developed countries, Singapore has higher rates of diabetes-related complication, ⁵ with 81.7% of major amputations attributing to diabetes. ⁶ DFU is associated with loss of mobility, reduced overall productivity, and poorer quality of life. ⁷ It also poses a significant economic burden. ⁸

Managing diabetes and its complications of DFU presents several challenges. These include ensuring adherence to treatment plans and lifestyle changes, providing timely and targeted education, appropriate screening and coordinating care among multiple providers. Patients often face time constraints and financial barriers, especially when dealing with complex treatment regimens. Healthcare system limitations, such as access to care and multiple follow-ups, can further complicate disease management. Therefore, a holistic approach that addresses these challenges is crucial for effective long-term care. Internationally, diabetic foot multidisciplinary teams (MDTs) have shown to improve limb salvage outcomes,^9,10 and is the recommended standard of care. ¹¹ Hence, we introduced a pioneering diabetic foot programme (DFP) to provide comprehensive care for patients with DFUs. This is a multidisciplinary programme that encompasses both inpatient and outpatient care, and work in close collaboration with primary care to reduce LEA through early intervention and secondary prevention strategies.

We aimed to characterise patients in our DFP and track their clinical outcomes in the first 3-months of follow-up. As a new program and hospital serving Singapore’s northern population, the data analysis will offer insights into patient characteristics and clinical outcomes for care improvement.

Methodology

This is an observational analysis of all patients within WH DFP between 2 May 2024 and 31 July 2024. The WH DFP is a multidisciplinary programme that encompasses both inpatient care and rapid access outpatient clinic known as the Lower Extremity Amputation Prevention Programme (LEAPP) Clinic (Figure 1).

Figure 1.

Diabetic foot programme workflow.

The members of WH DFP include podiatrist, diabetic nurse clinician, endocrinologist, infectious disease physician and surgeons (vascular, orthopaedic, plastics and reconstructive). Inclusion criteria for DFP are (i) patient above 21 years of age; (ii) with pre-existing diabetes mellitus and (iii) foot ulcers distal to the malleolus. Exclusion criteria includes (i) patient with foot wound without a diagnosis of diabetes; (ii) no foot ulcer or ulcer proximal to the malleolus; (iii) sepsis requiring high dependency or intensive care management or (iv) patients on end of life care. Inpatients were admitted through emergency department (ED) or directly from the LEAPP clinics. Outpatient referral to LEAPP clinic include patients with DFU from primary care, ED, specialist outpatient clinic and from inpatient wards post-discharge.

Clinical outcomes

The primary clinical outcomes assessed in this study encompassed multiple domains reflecting both clinical effectiveness and patient care quality. These included healthcare utilisation metrics such as DFU-related hospital admissions, 30-day readmission rates and 30-day mortality.

Interventional outcomes were also evaluated and included the proportion of patients who underwent revascularisation procedures, DFU-related surgeries and LEAs. Inpatient complications were recorded and included the incidence of acute myocardial infarction (AMI), acute kidney injury (AKI), cerebrovascular accident (CVA) and nosocomial infections. Wound-related outcomes were assessed by determining the proportion of patients who achieved complete wound healing, the mean time to healing from the initial clinic visit, and the proportion of patients with non-healed ulcers at their last follow-up.

Follow-up and care compliance metrics were also evaluated. These included the default rate for the initial LEAPP clinic appointment as well as the overall rate of loss to follow-up during the study period. With the retrospective analysis of a prospective database, missing and incomplete data have been kept to a minimum. Hence, there is low risk of bias.

Statistical analysis

Data were retrospectively retrieved after 3 months of follow-up (between September and October 2024). Institutional Review Board (IRB) approval was obtained. Written informed consent was exempted by IRB, as it involved the use of de-identified data and did not meet the criteria for human subject research. The dataset contained no personally identifiable information and posed minimal risk to individuals. Domain Specific Review Board (NHG DSRB Reference number 2024-4254) review was not required as the study involved anonymised data which do not meet the definition of human subject research.

Microsoft Excel (Microsoft 365, Microsoft Corporation, Redmond, WA, USA) was used to run descriptive statistics on the dataset. All continuous data were expressed as ‘mean ± standard deviation’, while categorical data were expressed as percentages. Quantitative variables that did not follow a normal distribution were expressed in median and interquartile range (IQR). For continuous variables that did not follow a normal distribution, we employed the non-parametric Mann–Whitney U test for statistical analysis. For biomarkers, laboratory cut-off values were used to differentiate patients with results above or below the cut off and analysed as both continuous and categorical data.

A cut-off value of greater than four was used for Charlson Comorbidity Index (CCI) as 1-year mortality rate for ‘greater than or equal to 5’ was 85% in the original study. ¹² A cut-off value of greater than four was used for the Diabetes Complication Severity index (DCSI). ¹³ Both indexes were analysed as categorical and continuous data. Wound assessment was classified according to the Wound, Ischaemia and Foot Infection Classification System (WIfI). ¹⁴

Results

Baseline characteristics

From May to July 2024, a total of 106 patients were enrolled into the DFP. Baseline characteristics are shown in Table 1. The medium age of the cohort was 63.5 years, with a male predominance (61.3%). The majority of patients were Malay (46.2%), followed by Chinese (27.4%) and Indian (25.5%). Non-smokers comprised 61% of the cohort, while 21.0% were active smokers.

Table 1.

Baseline characteristics.

Characteristic	Patients (n = 106)
Gender
Male	61.3%
Female	38.7%
Age	63.5 (IQR: 54.25–72)
Race
Chinese	27.4%
Malay	46.2%
Indian	25.5%
Other	0.9%
Smoking
Smoker	21.0%
Ex-smoker	18.1%
Non-smoker	61.0%
Pre-existing conditions
Hypertension	78.3%
Hyperlipidaemia	90.6%
Ischaemic heart disease	50.9%
End stage renal failure	24.5%
Previous stroke	17.0%
Cognitive impairment	12.3%
Retinopathy	48.1%
Peripheral arterial disease	63.8%
Peripheral neuropathy	49.5%
Diabetes
Duration	14 (IQR: 9.75–20)
HBA1C > 7%	77.8%
HBA1C	8.7 ± 2.1
Indexes
Charleson co-morbidity index > 4	75.5%
Charleson co-morbidity index	6.5 (IQR: 5–8)
Diabetes complication severity index > 4	78.3%
Diabetes complication severity index	6.0 (IQR: 5–8)
Laboratory tests
Systolic blood pressure ⩾ 140	33.0%
LDL ⩾ 2.6	24.5%

Most patients had a long duration of diabetes (median 14 years) and poor glycaemic control, with 77.8% having an HbA1c > 7% and a mean HbA1c of 8.7%. There was a high prevalence of metabolic comorbidities, including hypertension (78.3%) and hyperlipidaemia (90.6%). Despite medical management, 33% had inadequate blood pressure control, and 24.5% did not achieve low-density lipoprotein (LDL) targets.

Diabetes-related macro- and micro-vascular complications were common, with 50.9% having ischemic heart disease, 63.8% with peripheral arterial disease, 48.1% with retinopathy, 49.5% with peripheral neuropathy, 24.5% with end-stage renal failure and 17% having a history of stroke. The majority of patients had a DCSI score > 4 (78.3%). Additionally, the CCI was high, with 75.5% of patients having a CCI score > 4, and a median score of 6.5.

Ulcer assessment

The assessment of ulcers is summarised in Table 2. Among the 76 patients with WIfI scores, 14.1% were classified as having a medium risk, while 15.5% were at high risk of amputation. Wound discharge was observed in 78.6% of cases. Osteomyelitis, confirmed via X-ray or MRI, was present in 18.3% of patients, while gangrene was identified in 11.7%. Tissue cultures were obtained from 47.2% of patients, with 43.4% testing positive for infection. The majority of patients (72.6%) were prescribed antibiotics, with a mean treatment duration of 23 days.

Table 2.

Diabetic foot ulcer assessment.

Diabetic foot ulcer	Patients (N = 106)
WIfI (N = 76)
Wound
0	9.3%
1	52.6%
2	30.3%
3	7.9%
Ischaemia
0	65.8%
1	13.2%
2	7.9%
3	6.6%
Not assessed	6.6%
Foot infection
0	57.9%
1	19.7%
2	19.7%
3	1.3%
Not assessed	1.3%
1 year risk of amputation (n = 71)
Very low	54.9%
Low	15.5%
Medium	14.1%
High	15.5%
Wound characteristics
Purulent discharge	78.6%
Odour	11.7%
Gangrene	11.7%
Osteomyelitis (X-ray/MRI)	18.3%
Microbiology
Tissue culture performed	47.2%
Tissue culture positive	43.4%
Antibiotics prescribed	72.6%
Antibiotics duration	22.7 ± 14.4

Time to intervention

Table 3 shows the time to intervention within the DFP. The mean time to first review in LEAPP clinic was 7.5 days. The outpatient waiting time for a duplex scan was 14 days, whereas for inpatients, the mean time to a duplex scan was 3 days from admission. The mean duration to a revascularisation procedure was 4.4 days, while the mean time to DFU-related surgery (wound debridement or amputation) was 4.2 days. The mean length of hospital stay was 15.7 days, and the mean follow-up duration for the cohort was 103.0 days.

Table 3.

Time to intervention.

Intervention	Duration (days)
Referral to LEAPP/DFP (N = 96)	7.5 ± 7.3
Inpatient admission to duplex (N = 37)	3.1 ± 6.0
Clinic to duplex (N = 15)	13.7 ± 9.9
Admission to revascularisation (N = 22)	4.4 ± 3.9
Admission to DFU surgery (N = 37)	4.2 ± 6.6
Follow-up time (N = 105)	103.0 ± 29.8
Length of stay (N = 65)	15.7 ± 19.0
Major amputation (N = 5)
Primary intent	80.0%
After salvage attempt	20.0%

Clinical outcomes

Mean days of follow-up was 103 days (SD: 29.8). 61.3% of patients within the DFP had a DFU related admission (Table 4). The 30-day readmission rate was 11.3%, while the 30-day mortality was 3.8%. Revascularisation procedures were performed on 25.5% of patients, and DFU related surgeries in 34.9% of patients. 15.1% underwent minor LEA and 4.7% underwent major LEA. Of those who underwent major LEA, 80.0% had wounds clinically assessed as unsalvageable while 20.0% had previously undergone limb salvage attempts. Inpatient complications were relatively uncommon, with AMI (5.7%), AKI (4.7%), CVA (2.8%) and nosocomial infection (0.9%) reported.

Table 4.

Clinical outcomes.

Outcome	Patients (N = 106)
DFU-related admission	61.3%
30 days re-admission	11.3%
30 days mortality	3.8%
Revascularisation procedure	25.5%
DFU-related surgery	34.9%
Minor amputation	15.1%
Major amputation	4.7%
Default rate	13.2%
First encounter to healed (N = 37)	63.2 ± 34.2
Not healed yet	34.0%
Lost to follow-up	18.9%
Mortality before wound healed	5.7%
No wound at first visit	6.6%

A total of 13.2% of patients defaulted their LEAPP clinic appointments, and 18.9% were lost to follow-up. Among those with documented wound healing (34.8%), the mean time to healing was 63.2 days from the initial visit. However, 34.0% of patients had persistent wounds at the time of their last follow-up.

Discussion

The key interventions of WH DFP encompass early access to wound assessment, infection control, optimisation of diabetes management and other medical risk factors, timely revascularisation, active wound care with podiatric debridement, appropriate offloading strategies and patient education. Under this model of care, inpatients with DFUs are admitted under the care of a physician and are assessed by a MDT that includes podiatrists, vascular and orthopaedic surgeons upon admission. To ensure a comprehensive and holistic care, additional MDT members include plastic and reconstructive surgeons, infectious disease specialists, diabetes and wound care nurses, medical social workers, physiotherapists and occupational therapists. All inpatients are discussed at a weekly multidisciplinary meeting, where each specialist contributes their expertise in a collaborative approach, ensuring optimal clinical, functional and psychological outcomes for all patients.

Based on Singapore national statistics, the Indian population exhibits the highest prevalence of diabetes, at 17.2%, followed by the Malay population at 12.9%, and the Chinese population at 9.7%. ¹⁵ Additionally, poor glycaemic control was also more prevalent among Malays (67%) and Indians (65%) compared to Chinese (58%). ¹⁵ These factors may help explain the higher proportion of Malays and Indians with DFU in our cohort, despite their smaller representation in the general population (15% Malay and 7.5% Indian in Singapore).

Poorly controlled DM, a well-established independent risk factor for DFU affects 80% of our cohort. These patients have a 25 times higher risk of LEA than those without DM. ¹⁶ In addition to poorly controlled DM, at least 25% of our cohort suffers from inadequately controlled hypertension and dyslipidaemia. Consistent with the current literature, our study also identified a higher proportion of male with long duration of diabetes, which are both strongly associated with DFU. ¹⁷

Our cohort of patients had a high DCSI score, with the mean falling within the severe complication range. The presence of multiple co-existing diabetes-related complications such as ischaemic heart disease, end stage renal failure, diabetic retinopathy, peripheral arterial disease (PAD) and neuropathy, further supports the correlation with longer diabetes duration and poor glycaemic control. PAD is at least twice as prevalent in individuals with DM compared to those without DM. ¹⁸ Unsurprisingly, majority of our patients with DFU had PAD (63.8%). PAD and peripheral neuropathy (PN) are well-established factors in the pathogenesis of DFU, ¹⁹ contributing to diabetic foot infections, gangrene, and ultimately, LEA. Moreover, DFU with PAD is associated with poorer wound healing, as well as higher mortality and LEA rates compared to individuals with DFU without PAD. ¹⁹

Among our cohort of 106 patients, 61.3% required an inpatient management of the DFU. This included treatment with intravenous antibiotics for diabetic foot infections and sepsis, glycaemic optimisation and DFU-related surgical management such as debridement, minor and major LEA. The mean length of hospital stay was 15.7 days, which is consistent with reported literature values ranging from 10 to 18 days.^8,20 The median time to intervention, including revascularisation or surgery, was within 5 days, reflecting the impact of co-ordinated MDT efforts aimed at expediting care for patients admitted with DFU. This aligns with current evidence suggesting that timely intervention significantly improves ulcer healing and reduced risk of limb loss.

DFUs are characterised by wound poor healing due to persistent dysregulated inflammation within the DFU microenvironment. ²¹ Notably, 30-day readmission rates for DFU-related admissions have been reported to be as high as 22% ²² ; however, in our cohort, the 30-day readmission rate, was comparatively lower at 18.5%.

In the assessment of DFU, WIfI scoring was performed in 76 individuals. A proportion of patients (28.3%) could not be classified using the WIfI scoring system. Specifically, these patients had undetermined ischaemic status at the time of presentation. Additionally, among those classified using the WIfI system, ischemia was not assessed in certain cases. In particular, for patients with a WIfI classification of 2 × 2 (indicating moderate wound and infection severity), our clinical protocol emphasises prompt source control interventions without delaying care for vascular imaging. This approach reflects current best practices, where infection management is prioritised, and vascular assessment is pursued concurrently. Although most patients lacked significant ischemia and foot infection based on WIfI score, some of our patients had moderate-to-severe wounds such as those with large ulcers, deep tissue involvement, or necrosis, that require intensive inpatient wound care, surgical debridement and coordination for limb salvage procedures. Although 40.7% of patients were classified as having infection per the WIfI score, tissue cultures were obtained in 47.2% of cases, and a high proportion of patients (72%) received antibiotics. These results reflect a degree of (i) diagnostic uncertainty where cultures were obtained from wounds that appeared at risk for infection or showed signs that were concerning but did not fully meet WIfI infection criteria and (ii) empiric or precautionary prescribing, particularly in patients with complex wounds where the risk of occult or developing infection was a clinical concern.

In those who had WIfl scores, approximately 30% were classified as having a medium-to-high risk of amputation, corresponding to an estimated 25%-50% likelihood of major LEA within 1 year ¹⁴ . Despite this high-predicted risk, our limb salvage outcomes were favourable at 100 days, with a low major amputation rate of 0.9% following limb salvage interventions. When considering all LEA, the incidence in our cohort was 19.8%, which is lower than the reported global incidence of 31.0% ²³ . DFU is also associated with an increased mortality rate and a high recurrence rate of 40% within 1 year ²⁴ . While the literature reports a 1-year mortality rate of approximately 10% ²⁵ , our dataset does not include 1-year mortality outcomes. Our observed 30-day mortality rate is 3.8%. While major LEA, and mortality rates in our cohort were low, these outcomes require longer-term surveillance to be fully meaningful.

In the outpatient setting, the median duration from referral to the initial LEAPP clinic visit is 7.5 days. Patients with DFU are typically reviewed every 2 to 4 weeks at the LEAPP clinic and may be required to attend primary care facilities for wound dressing changes every 2 to 3 days. DFU is a chronic complication typically seen in patients with long-standing, poorly controlled diabetes mellitus with multiple comorbidities. These patients are often less adherent to treatment and follow-up. Socioeconomic barriers, including limited access to transportation, financial constraints, and low health literacy are likely contributors to this poor adherence. Additionally, the need for frequent clinic visits, time off work and adherence to foot offloading measures further disrupt patients’ occupational and daily functioning, posing significant challenges to sustained engagement with care. As a result, DFU imposes significant burden of care, and despite the risk of severe complications, 13.2% of our patients failed to attend their first scheduled appointment, while 18.9% discontinued follow-up. A recent study reported up to 40.2% of patients had defaulted at least one DFU-related appointment ²⁶ . To encourage patient adherence to follow-up appointments, several strategies were implemented. A key approach was the provision of a convenient one-stop visit through the LEAPP follow-up, which consolidated multiple services into a single appointment to reduce the burden on patients. Additionally, efforts were made to improve accessibility and engagement within the community, and using phone reminders to prompt attendance. These measures aimed to minimise barriers and support continuity of care.

Although this study lacks a formal control group, historical data from both international (OECD) and local sources indicate that Singapore has consistently reported some of the highest rates of major LEAs globally. Over the past four years, the implementation of DEFINITE Care has coincided with notable improvements in diabetic foot care outcomes ¹⁸ . The addition of the multidisciplinary inpatient program has further enhanced care coordination and timely intervention. While other factors may have contributed, the observed trends suggest a positive impact of these system-level changes.

The limitations of this study include the short follow-up duration and the absence of a detailed subgroup analysis. At the time of data collection, 34.0% of patients had not yet achieved ulcer healing, which may have led to an underestimation of the true time required for complete ulcer resolution, as the mean duration was calculated only for those whose ulcers had healed. A proportion of patients could not be classified using the WIfI system due to incomplete clinical data at their initial presentation. While this reflects a limitation in the immediate application of WIfI in early patient encounters, it also highlights a challenge in implementing standardised classification systems in real world, multidisciplinary clinical workflows. Future longitudinal assessments will aim to include ischaemia classification once comprehensive diagnostic information becomes available.

As this is a 3-month review, we were unable to assess 1-year amputation or mortality rates, limiting our ability to evaluate whether these outcomes align with predictions from existing scoring systems. Although demographic data and various biomarkers were collected, an in-depth subgroup analysis was not performed to determine the significance of these factors on clinical outcomes. In addition, the study design being observational and reliant on the number of patients presenting with DFU during the 100-day period, it was not feasible to determine a priori sample size calculation.

Conclusion

The early review of our multidisciplinary diabetic limb salvage (DLS) programme provides a comprehensive overview of the management and clinical outcomes of patients with DFU. Our findings highlight the high burden of inpatient care, yet demonstrating favourable limb salvage outcomes despite a significant proportion being at moderate-to-high risk of major amputation. Our multidisciplinary approach, incorporating early wound assessment, infection control, metabolic optimisation, timely revascularisation, and active wound care, has contributed to relatively low major LEA, and 30-day readmission rates. However, patient adherence remains a challenge, with a notable proportion defaulting follow-ups, potentially impacting long-term outcomes.

While our short follow-up period limits the ability to assess long-term outcomes such as 1-year amputation, mortality and ulcer recurrence rates, this study provides critical insights into DFU management in the first 100 days. Future research with extended follow-up, subgroup and multivariate analysis will be necessary to further elucidate predictors of healing, LEA high-risk groups, disparities in outcomes linked to demographic factors and long-term patient outcomes. These findings underscore the importance of a structured, multidisciplinary diabetic limb salvage programme in improving clinical outcomes and reducing the burden of diabetic foot disease. Future research should also incorporate Patient-Reported Outcome Measures (PROMs) and/or Patient-Reported Experience Measures (PREMs) to capture a more comprehensive view of DFU care. These tools can provide meaningful insights into the effects of DFU and its treatment on patients’ functional status, emotional well-being and overall satisfaction with care.